1. Field of the Invention
The present invention relates to a liquid crystal display.
2. Discussion of the Background
Liquid crystal displays (LCDs) are one of the most widely used flat panel displays. An LCD includes a pair of substrates provided with field-generating electrodes, such as pixel electrodes and a common electrode, and a liquid crystal (LC) layer interposed between the two substrates. The LCD displays images when voltages are applied to the field-generating electrodes, thereby generating an electric field in the LC layer that determines the orientations of LC molecules therein to adjust polarization of incident light.
Among LCDs, a vertical alignment (VA) mode LCD, which aligns LC molecules such that the long axes thereof are perpendicular to the substrates in the absence of an electric field, is spotlighted because of its high contrast ratio and wide viewing angle.
The wide viewing angle of the VA mode LCD may be realized by cutouts or openings in the field-generating electrodes. Since the cutouts may determine the tilt directions of the LC molecules, the tilt directions may be distributed in several directions using the cutouts such that the viewing angle is widened.
However, the VA mode LCD has poor lateral visibility as compared with front visibility. To improve the lateral visibility of the VA mode LCD, one pixel may be divided into two sub-pixels and different voltages may be applied to each sub-pixel. One sub-pixel receives a higher voltage through a switching element and the other sub-pixel may be coupled to the sub-pixel connected to the switching element through a coupling capacitor so that it may receive a lower voltage.
However, when connecting two sub-pixels with a coupling capacitor, the pixels may discharge more slowly, thereby generating image sticking. Also, the color and luminance of the LCD are not naturally visible on the lateral side since the lateral gamma curve changes abruptly.